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1.
J Neural Eng ; 16(3): 036026, 2019 06.
Article de Anglais | MEDLINE | ID: mdl-30650392

RÉSUMÉ

OBJECTIVE: Brain computer interface (BCI) technology can be important for those unable to communicate due to loss of muscle control. Given that the P300 Speller provides a relatively slow rate of communication, highly accurate classification is of great importance. Previous studies have shown that alternative stimuli (e.g. faces) can improve BCI speed and accuracy. The present study uses two new alternative stimuli, locations and graspable tools. Functional MRI studies have shown that images of familiar locations produce brain responses in the parahippocampal place area and graspable tools produce brain responses in premotor cortex. APPROACH: The current studies show that location and tool stimuli produce unique and discriminable brain responses that can be used to improve offline classification accuracy. Experiment 1 presented face stimuli and location stimuli and Experiment 2 presented location and tool stimuli. MAIN RESULTS: In both experiments, offline results showed that a stimulus specific classifier provided higher accuracy, speed, and bit rate. SIGNIFICANCE: This study was used to provide preliminary offline support for using unique stimuli to improve speed and accuracy of the P300 Speller. Additional experiments should be conducted to examine the online efficacy of this novel paradigm.


Sujet(s)
Interfaces cerveau-ordinateur , Encéphale/physiologie , Potentiels évoqués cognitifs P300/physiologie , Reconnaissance faciale/physiologie , Reconnaissance visuelle des formes/physiologie , Stimulation lumineuse/méthodes , Adulte , Femelle , Humains , Mâle , Jeune adulte
2.
J Dev Orig Health Dis ; 10(1): 24-30, 2019 02.
Article de Anglais | MEDLINE | ID: mdl-30079854

RÉSUMÉ

Children of mothers with youth-onset (<18 years) type 2 diabetes (T2D) are at increased risk of youth-onset T2D. In Canada, the highest reported prevalence of youth-onset T2D is in First Nation youth, some of whom harbor a unique genetic predisposition HNF1α polymorphism which has been associated with age of onset and clinical presentation. To describe the characteristics of the Next Generation birth cohort (n=260) at 7-9 years (n=88) and 14-16 years of age (n=27). This is a cross-sectional study of offspring exposed in utero to T2D (Next Generation Birth Cohort). Annual assessments from age 7 include height and weight, and biochemical testing (glucose, insulin, lipids, HbA1c). Descriptive statistics were employed. χ2 tests and repeated-measures ANOVA were used to compare categorical and continuous characteristics, respectively. In total, 11.9% of the total cohort have developed T2D. Of those 14-16.9 years of age, 16.0% have developed T2D. 92% of the offspring ages 7-9 and 70.3% of offspring ages 14-16 are overweight or obese. Children had a significantly higher body mass index z-score than adolescents (2.9 v. 1.5, P=0.001). Comparing the different HNF1α genotypes (G/G wildtype, G/S heterozygote, S/S homozygote); HbA1c (GG: 5.5% v. G/S: 5.7% v. S/S: 8.8%; P=0.0052), insulin (GG: 103 v. G/S: 202; P=0.05) and T2D status (G/G: 5.7% v. G/S: 28.1% v. S/S: 72.7%; P<0.0001) were significantly different between groups. T2D is very common among adolescents of mothers with youth-onset T2D. Early childhood obesity and the HNF1α G319S allele are associated with the incidence of T2D in the Next Gen offspring.


Sujet(s)
Diabète de type 2/génétique , Adolescent , Indice de masse corporelle , Canada/épidémiologie , Enfant , Études de cohortes , Diabète de type 2/épidémiologie , Prédisposition génétique à une maladie , Hémoglobine glyquée/métabolisme , Humains , Incidence , Santé maternelle , Prévalence , Facteurs de risque
3.
Clin Neurophysiol ; 128(10): 2050-2057, 2017 10.
Article de Anglais | MEDLINE | ID: mdl-28863361

RÉSUMÉ

OBJECTIVE: Current Brain-Computer Interface (BCI) systems typically flash an array of items from grey to white (GW). The objective of this study was to evaluate BCI performance using uniquely colored stimuli. METHODS: In addition to the GW stimuli, the current study tested two types of color stimuli (grey to color [GC] and color intensification [CI]). The main hypotheses were that in a checkboard paradigm, unique color stimuli will: (1) increase BCI performance over the standard GW paradigm; (2) elicit larger event-related potentials (ERPs); and, (3) improve offline performance with an electrode selection algorithm (i.e., Jumpwise). RESULTS: Online results (n=36) showed that GC provides higher accuracy and information transfer rate than the CI and GW conditions. Waveform analysis showed that GC produced higher amplitude ERPs than CI and GW. Information transfer rate was improved by the Jumpwise-selected channel locations in all conditions. CONCLUSIONS: Unique color stimuli (GC) improved BCI performance and enhanced ERPs. Jumpwise-selected electrode locations improved offline performance. SIGNIFICANCE: These results show that in a checkerboard paradigm, unique color stimuli increase BCI performance, are preferred by participants, and are important to the design of end-user applications; thus, could lead to an increase in end-user performance and acceptance of BCI technology.


Sujet(s)
Interfaces cerveau-ordinateur/normes , Perception des couleurs/physiologie , Potentiels évoqués cognitifs P300/physiologie , Reconnaissance visuelle des formes/physiologie , Stimulation lumineuse/méthodes , Adulte , Électroencéphalographie/méthodes , Électroencéphalographie/normes , Femelle , Humains , Mâle , Adulte d'âge moyen
4.
Diabet Med ; 34(10): 1414-1420, 2017 10.
Article de Anglais | MEDLINE | ID: mdl-28626956

RÉSUMÉ

AIMS: To compare the incidence of and mortality after intensive care unit admission in adults with paediatric-onset Type 1 diabetes vs the general population. METHODS: Using population-based administrative data from Manitoba, Canada, we identified 814 cases of paediatric-onset Type 1 diabetes, and 3579 general population controls matched on age, sex and region of residence. We estimated the incidence of intensive care unit admission in adulthood, and compared the findings between populations using incidence rate ratios and multivariable Cox proportional hazards regression, adjusting for age, sex, comorbidity and socio-economic status. We estimated age- and sex-standardized mortality rates after intensive care unit admission. RESULTS: Between January 2000 and October 2009, the average annual incidence of intensive care unit admission among prevalent cohorts was 910 per 100 000 in the Type 1 diabetes population, and 106 per 100 000 in matched controls, an eightfold increased risk (incidence rate ratio 8.6; 95% CI 5.5, 14.0). The adjusted risk of intensive care unit admission was elevated to a greater extent among women with Type 1 diabetes compared with matched women (hazard ratio 14.7; 95% CI 7.2, 29.4) than among men with Type 1 diabetes compared with matched men (hazard ratio 4.92; 95% CI 10.3, 2.36) The most common reasons for admission in the diabetes cohort were diabetic ketoacidosis, infection and ischaemic heart disease. At 30%, 5-year mortality was higher in the diabetes cohort than in the matched cohort (relative risk 5.7; 95% CI 1.2, 8.9). CONCLUSIONS: Compared with the general population, the risk of intensive care unit admission was higher in adults with paediatric-onset Type 1 diabetes, and mortality after admission was also higher.


Sujet(s)
Maladie grave/épidémiologie , Complications du diabète/épidémiologie , Diabète de type 1/complications , Diabète de type 1/épidémiologie , Adolescent , Adulte , Canada/épidémiologie , Études cas-témoins , Enfant , Enfant d'âge préscolaire , Acidocétose diabétique/épidémiologie , Femelle , Humains , Incidence , Infections/épidémiologie , Unités de soins intensifs/statistiques et données numériques , Mâle , Ischémie myocardique/épidémiologie , Admission du patient/statistiques et données numériques , Jeune adulte
5.
Clin Pharmacol Ther ; 102(4): 580-584, 2017 Oct.
Article de Anglais | MEDLINE | ID: mdl-28548221

RÉSUMÉ

Much of the history of pharmacology and therapeutics involves finding new uses for old drugs. The latest rediscovery is that of psychedelic drugs. Since they can cause profound distortions of perception and were once used as part of religious ceremonies, such research may seem unusual at this time.


Sujet(s)
Repositionnement des médicaments , Hallucinogènes/administration et posologie , Psilocybine/administration et posologie , Hallucinogènes/effets indésirables , Hallucinogènes/pharmacologie , Humains , Psilocybine/effets indésirables , Psilocybine/pharmacologie
6.
Clin Pharmacol Ther ; 101(2): 167-169, 2017 Feb.
Article de Anglais | MEDLINE | ID: mdl-27564430

RÉSUMÉ

The concepts behind current "designer drugs" are not new. For several centuries, chemical synthesis has made drugs more specific and more selective. However, headline designer drugs now are different and a serious public health problem because they are illicit unregulated chemical knockoffs of approved psychoactive stimulant, sedative, or perception-altering controlled substances.


Sujet(s)
Drogues fabriquées clandestinement/effets indésirables , Substances illicites/effets indésirables , Psychoanaleptiques/effets indésirables , Santé publique , Troubles liés à une substance/épidémiologie , Drogues fabriquées clandestinement/économie , Drogues fabriquées clandestinement/pharmacologie , Humains , Substances illicites/économie , Substances illicites/législation et jurisprudence , Psychoanaleptiques/économie
7.
J Neural Eng ; 13(6): 066018, 2016 12.
Article de Anglais | MEDLINE | ID: mdl-27819250

RÉSUMÉ

OBJECTIVE: Dry electrodes have an advantage over gel-based 'wet' electrodes by providing quicker set-up time for electroencephalography recording; however, the potentially poorer contact can result in noisier recordings. We examine the impact that this may have on brain-computer interface communication and potential approaches for mitigation. APPROACH: We present a performance comparison of wet and dry electrodes for use with the P300 speller system in both healthy participants and participants with communication disabilities (ALS and PLS), and investigate the potential for a data-driven dynamic data collection algorithm to compensate for the lower signal-to-noise ratio (SNR) in dry systems. MAIN RESULTS: Performance results from sixteen healthy participants obtained in the standard static data collection environment demonstrate a substantial loss in accuracy with the dry system. Using a dynamic stopping algorithm, performance may have been improved by collecting more data in the dry system for ten healthy participants and eight participants with communication disabilities; however, the algorithm did not fully compensate for the lower SNR of the dry system. An analysis of the wet and dry system recordings revealed that delta and theta frequency band power (0.1-4 Hz and 4-8 Hz, respectively) are consistently higher in dry system recordings across participants, indicating that transient and drift artifacts may be an issue for dry systems. SIGNIFICANCE: Using dry electrodes is desirable for reduced set-up time; however, this study demonstrates that online performance is significantly poorer than for wet electrodes for users with and without disabilities. We test a new application of dynamic stopping algorithms to compensate for poorer SNR. Dynamic stopping improved dry system performance; however, further signal processing efforts are likely necessary for full mitigation.


Sujet(s)
Interfaces cerveau-ordinateur , Collecte de données/méthodes , Électrodes , Électroencéphalographie/instrumentation , Potentiels évoqués cognitifs P300/physiologie , Adulte , Algorithmes , Artéfacts , Aides à la communication pour personnes handicapées , Troubles de la communication/psychologie , Troubles de la communication/rééducation et réadaptation , Femelle , Volontaires sains , Humains , Mâle , Rapport signal-bruit
8.
J Pharmacol Exp Ther ; 359(3): 471-481, 2016 Dec.
Article de Anglais | MEDLINE | ID: mdl-27647873

RÉSUMÉ

Drugs with µ-opioid receptor (OR) activity can be associated with abuse and misuse. The peripherally acting mixed µ-OR and κ-OR agonist and δ-OR antagonist eluxadoline is approved in the United States for the treatment of irritable bowel syndrome with diarrhea. In two separate crossover studies, we evaluated the oral and intranasal abuse potential of eluxadoline versus placebo and the active control oxycodone. Healthy recreational opioid users received eluxadoline 100, 300, and 1000 mg, oxycodone 30 and 60 mg, and placebo (oral study), or eluxadoline 100 and 200 mg, oxycodone 15 and 30 mg, and placebos matched to eluxadoline and oxycodone (intranasal study). In the oral study, Drug Liking Visual Analog Scale (VAS) peak (maximum) effect (Emax) score (primary endpoint) was significantly greater with eluxadoline 300 and 1000 mg versus placebo, but scores were significantly lower versus oxycodone. Following intranasal insufflation of eluxadoline, Drug Liking VAS Emax scores were not statistically different versus placebo, and were significantly lower versus oxycodone. Across other subjective measures, eluxadoline was generally similar to or disliked versus placebo. Pupillometry indicated no or minimal central effects with oral and intranasal eluxadoline, respectively. Adverse events of euphoric mood were reported with oral and intranasal eluxadoline but at a far lower frequency versus oxycodone. These data demonstrate that eluxadoline has less abuse potential than oxycodone in recreational opioid users.


Sujet(s)
Imidazoles/administration et posologie , Imidazoles/pharmacologie , Phénylalanine/analogues et dérivés , Récepteur delta/antagonistes et inhibiteurs , Récepteur kappa/agonistes , Récepteur mu/agonistes , Troubles liés à une substance , Administration par voie nasale , Administration par voie orale , Adulte , Relation dose-effet des médicaments , Femelle , Humains , Imidazoles/pharmacocinétique , Mâle , Phénylalanine/administration et posologie , Phénylalanine/pharmacocinétique , Phénylalanine/pharmacologie , Psychométrie , Troubles liés à une substance/étiologie , Troubles liés à une substance/psychologie
9.
Clin Pharmacol Ther ; 100(3): 275-86, 2016 09.
Article de Anglais | MEDLINE | ID: mdl-27170195

RÉSUMÉ

An extended-release opioid analgesic (OxyContin, OC) was reformulated with abuse-deterrent properties to deter abuse. This report examines changes in abuse through oral and nonoral routes, doctor-shopping, and fatalities in 10 studies 3.5 years after reformulation. Changes in OC abuse from 1 year before to 3 years after OC reformulation were calculated, adjusted for prescription changes. Abuse of OC decreased 48% in national poison center surveillance systems, decreased 32% in a national drug treatment system, and decreased 27% among individuals prescribed OC in claims databases. Doctor-shopping for OC decreased 50%. Overdose fatalities reported to the manufacturer decreased 65%. Abuse of other opioids without abuse-deterrent properties decreased 2 years later than OC and with less magnitude, suggesting OC decreases were not due to broader opioid interventions. Consistent with the formulation, decreases were larger for nonoral than oral abuse. Abuse-deterrent opioids may mitigate abuse and overdose risks among chronic pain patients.


Sujet(s)
Analgésiques morphiniques/administration et posologie , Chimie pharmaceutique/méthodes , Troubles liés aux opiacés/épidémiologie , Oxycodone/administration et posologie , Surveillance post-commercialisation des produits de santé , Voies d'administration de substances chimiques et des médicaments , Humains , Troubles liés aux opiacés/mortalité , Types de pratiques des médecins/statistiques et données numériques , Détournement de médicaments sur ordonnance/statistiques et données numériques , Surdose/statistiques et données numériques , Caractéristiques de l'habitat , États-Unis/épidémiologie
10.
Int J Obes (Lond) ; 40(4): 607-14, 2016 Apr.
Article de Anglais | MEDLINE | ID: mdl-26617254

RÉSUMÉ

BACKGROUND: The chronic effects of high-intensity endurance training on metabolic health outcomes in overweight adolescents remains poorly understood. OBJECTIVE: To test the hypothesis that high-intensity endurance training (ET) is superior to moderate-intensity ET for improving risk factors for type 2 diabetes in overweight adolescents. DESIGN AND METHODS: In this randomized trial, 106 overweight and obese adolescents (15.2 years; 76% female; 62% Caucasian) were randomly assigned to high-intensity ET (70-85% of heart rate reserve, n=38), moderate-intensity ET (40-55% heart rate reserve; n=32) or control for 6 months (n=36). The primary and secondary outcome measures were insulin sensitivity assessed using a frequently sampled intravenous glucose tolerance test and hepatic triglyceride content with magnetic resonance spectroscopy. Exploratory outcomes were cardiorespiratory fitness, physical activity and MRI and dual x-ray absorptiometry-derived measures of adiposity. RESULTS: The study had 96% retention and attendance was 61±21% and 55±24% in the high- and moderate-intensity ET arms. Intention-to-treat analyses revealed that, at follow-up, insulin sensitivity was not different between high-intensity (-1.0 mU kg(-1) min(-1); 95% confidence interval (CI): -1.6, +1.4 mU kg(-1) min(-1)) and moderate-intensity (+0.26 mU kg(-1) min(-1); 95% CI: -1.3, +1.8 mU kg(-1) min(-1)) ET arms compared with controls (interaction, P=0.97). Similarly, hepatic triglyceride at follow-up was not different in high-intensity (-1.7% fat/water (F/W); 95% CI: -7.0, +3.6% F/W) and moderate-intensity (-0.40% FW; 95% CI: -6.0, +5.3% F/W) ET compared with controls. Both high intensity (+4.4 ml per kg-FFM (fat-free mass) per minute; 95% CI: 1.7, 7.1 ml kg-FFM(-1) min(-1)) and moderate intensity (+4.4 ml kg-FFM(-1) min(-1); 95% CI: 1.6, 7.3 ml kg-FFM(-1) min(-1)) increased cardiorespiratory fitness, relative to controls (interaction P<0.001). CONCLUSIONS: ET improves cardiorespiratory fitness among obese adolescents; however, owing to lack of compliance, the influence of exercise intensity on insulin sensitivity and hepatic triglycerides remains unclear.


Sujet(s)
Diabète de type 2/physiopathologie , Traitement par les exercices physiques , Obésité pédiatrique/physiopathologie , Endurance physique , Adolescent , Indice de masse corporelle , Canada , Phénomènes physiologiques cardiovasculaires , Diabète de type 2/étiologie , Diabète de type 2/prévention et contrôle , Femelle , Humains , Insulinorésistance , Mâle , Observance par le patient , Obésité pédiatrique/sang , Obésité pédiatrique/complications , Aptitude physique , Entraînement en résistance , Facteurs de risque , Résultat thérapeutique , Triglycéride/analyse , Triglycéride/sang
11.
Diabet Med ; 33(9): 1245-52, 2016 09.
Article de Anglais | MEDLINE | ID: mdl-26359622

RÉSUMÉ

BACKGROUND: Over the past 30 years, the prevalence of diabetes has steadily increased among Canadians, and is particularly evident among First Nations (FN) women. The interplay between FN ancestry, gestational diabetes and the development of subsequent diabetes among mothers remains unclear. METHODS: After excluding known pre-existing diabetes, we explored whether FN ancestry may modify the association between gestational diabetes and post-partum diabetes among women in Manitoba (1981-2011) via a historical prospective cohort database study. We analysed administrative data in the Population Health Research Data Repository using Kaplan-Meier survival analysis and Cox proportional hazards regression. RESULTS: Gestational diabetes was diagnosed in 11 906 of 404 736 deliveries (2.9%), 6.7% of FN and 2.2% of non-FN pregnant women (P < 0.0001). Post-partum diabetes during ≤ 30 years follow-up was more than three times higher among FN women than among non-FN women (P < 0.0001). Diabetes developed in 76.0% of FN and 56.2% of non-FN women with gestational diabetes within the follow-up period. The hazard ratio of gestational diabetes for post-partum diabetes was 10.6 among non-FN women and 5.4 among FN women. Other factors associated with a higher risk of diabetes included lower family income among FN and non-FN women and rural/remote residences among FN women. Among non-FN women, urban residence was associated with a higher risk of diabetes. CONCLUSION: Gestational diabetes increases post-partum diabetes in FN and non-FN women. FN women had substantially more gestational diabetes or post-partum diabetes than non-FN women, partially due to socio-economic and environmental barriers. Reductions in gestational diabetes and socio-economic inequalities are required to prevent diabetes in women, particularly in FN population.


Sujet(s)
Diabète de type 2/ethnologie , Diabète gestationnel/ethnologie , Indiens d'Amérique Nord , Adulte , Études de cohortes , Diabète de type 2/épidémiologie , Diabète gestationnel/épidémiologie , Femelle , Études de suivi , Humains , Estimation de Kaplan-Meier , Manitoba/épidémiologie , Grossesse , Modèles des risques proportionnels , Études prospectives , Facteurs de risque , Jeune adulte
12.
Int J Obes (Lond) ; 39(7): 1070-8, 2015 Jul.
Article de Anglais | MEDLINE | ID: mdl-25869598

RÉSUMÉ

OBJECTIVES: The optimal screening measures for obesity in children remain controversial. Our study aimed to determine the anthropometric measurement at age 10 years that most strongly predicts the incidence of cardio-metabolic risk factors at age 13 years. SUBJECTS/METHODS: This was a prospective cohort study of a population-based cohort of 438 children followed between age 7 and 13 years of age. The main exposure variables were adiposity at age 10 years determined from body mass index (BMI) Z-score, waist circumference (WC) Z-score, waist-to-hip ratio and waist-to-height ratio. Outcome measures included systolic (SBP) and diastolic blood pressure (DBP), fasting high-density (HDL-c) and low-density lipoprotein cholesterol (LDL-c), triglycerides, insulin and glucose (homeostasis model of assessment, HOMA), and the presence of metabolic syndrome (MetS). RESULTS: WC Z-score at age 10 years was a stronger predictor of SBP (ß 0.21, R(2) 0.38, P<0.001 vs ß 0.30, R(2) 0.20, P<0.001) and HOMA (ß 0.51, R(2) 0.25, P<0.001 vs 0.40, R(2) 0.19, P<0.001) at age 13 years compared with BMI Z-score. WC relative to height and hip was stronger predictors of cardio- metabolic risk than BMI Z-score or WC Z-score. The relative risk (RR) of incident MetS was greater for an elevated BMI Z-score than for an elevated WC (girls: RR 2.52, 95% confidence interval (CI): 1.46-4.34 vs RR 1.56, 95% CI 1.18-2.07) and (boys: RR 2.86, 95% CI 1.79-4.62 vs RR 2.09, 95% CI 1.59-2.77). CONCLUSIONS: WC was a better predictor of SBP and HOMA compared with BMI or WC expressed relative to height or hip circumference. BMI was associated with higher odds of MetS compared with WC. Thus, BMI and WC may each be clinically relevant markers of different cardio-metabolic risk factors, and important in informing obesity-related prevention and treatment strategies.


Sujet(s)
Maladies cardiovasculaires/prévention et contrôle , Syndrome métabolique X/prévention et contrôle , Obésité/prévention et contrôle , Pression sanguine , Taille , Indice de masse corporelle , Maladies cardiovasculaires/sang , Maladies cardiovasculaires/épidémiologie , Maladies cardiovasculaires/étiologie , Enfant , Cholestérol HDL/sang , Cholestérol LDL/sang , Femelle , Humains , Mâle , Syndrome métabolique X/sang , Syndrome métabolique X/épidémiologie , Syndrome métabolique X/étiologie , Obésité/sang , Obésité/complications , Obésité/épidémiologie , Valeur prédictive des tests , Études prospectives , Facteurs de risque , Répartition par sexe , Triglycéride/sang , Tour de taille , Rapport taille-hanches
13.
J Neural Eng ; 12(1): 016013, 2015 Feb.
Article de Anglais | MEDLINE | ID: mdl-25588137

RÉSUMÉ

OBJECTIVE: The P300 speller is a brain-computer interface (BCI) that can possibly restore communication abilities to individuals with severe neuromuscular disabilities, such as amyotrophic lateral sclerosis (ALS), by exploiting elicited brain signals in electroencephalography (EEG) data. However, accurate spelling with BCIs is slow due to the need to average data over multiple trials to increase the signal-to-noise ratio (SNR) of the elicited brain signals. Probabilistic approaches to dynamically control data collection have shown improved performance in non-disabled populations; however, validation of these approaches in a target BCI user population has not occurred. APPROACH: We have developed a data-driven algorithm for the P300 speller based on Bayesian inference that improves spelling time by adaptively selecting the number of trials based on the acute SNR of a user's EEG data. We further enhanced the algorithm by incorporating information about the user's language. In this current study, we test and validate the algorithms online in a target BCI user population, by comparing the performance of the dynamic stopping (DS) (or early stopping) algorithms against the current state-of-the-art method, static data collection, where the amount of data collected is fixed prior to online operation. MAIN RESULTS: Results from online testing of the DS algorithms in participants with ALS demonstrate a significant increase in communication rate as measured in bits/min (100-300%), and theoretical bit rate (100-550%), while maintaining selection accuracy. Participants also overwhelmingly preferred the DS algorithms. SIGNIFICANCE: We have developed a viable BCI algorithm that has been tested in a target BCI population which has the potential for translation to improve BCI speller performance towards more practical use for communication.


Sujet(s)
Sclérose latérale amyotrophique/physiopathologie , Sclérose latérale amyotrophique/rééducation et réadaptation , Électroencéphalographie/méthodes , Potentiels évoqués cognitifs P300 , Mémorisation et recherche des informations/méthodes , Reconnaissance automatique des formes/méthodes , Adulte , Algorithmes , Cartographie cérébrale/méthodes , Interfaces cerveau-ordinateur , Aides à la communication pour personnes handicapées , Périphériques d'ordinateur , Femelle , Humains , Mâle , Adulte d'âge moyen , Reproductibilité des résultats , Sensibilité et spécificité , Traitement du signal assisté par ordinateur , Cortex visuel/physiopathologie , Perception visuelle , Traitement de texte
14.
J Neurosci Methods ; 232: 6-15, 2014 Jul 30.
Article de Anglais | MEDLINE | ID: mdl-24797224

RÉSUMÉ

The P300 Speller brain-computer interface (BCI) allows a user to communicate without muscle activity by reading electrical signals on the scalp via electroencephalogram. Modern BCI systems use multiple electrodes ("channels") to collect data, which has been shown to improve speller accuracy; however, system cost and setup time can increase substantially with the number of channels in use, so it is in the user's interest to use a channel set of modest size. This constraint increases the importance of using an effective channel set, but current systems typically utilize the same channel montage for each user. We examine the effect of active channel selection for individuals on speller performance, using generalized standard feature-selection methods, and present a new channel selection method, termed jumpwise regression, that extends the Stepwise Linear Discriminant Analysis classifier. Simulating the selections of each method on real P300 Speller data, we obtain results demonstrating that active channel selection can improve speller accuracy for most users relative to a standard channel set, with particular benefit for users who experience low performance using the standard set. Of the methods tested, jumpwise regression offers accuracy gains similar to the best-performing feature-selection methods, and is robust enough for online use.


Sujet(s)
Cartographie cérébrale , Interfaces cerveau-ordinateur , Potentiels évoqués cognitifs P300/physiologie , Analyse discriminante , Électroencéphalographie , Femelle , Humains , Mâle , Stimulation lumineuse , Courbe ROC , Étudiants , Universités
15.
Drug Alcohol Depend ; 130(1-3): 13-23, 2013 Jun 01.
Article de Anglais | MEDLINE | ID: mdl-23415386

RÉSUMÉ

An expert panel convened in 2005 by the College on Problems of Drug Dependence (CPDD) to consider strategies to reduce the risk of prescription medication abuse concluded that drug formulation plays a significant role in determining risk of abuse. Efforts on the part of the pharmaceutical industry to develop drugs that deter abuse have focused primarily on opioid formulations resistant to common forms of tampering, most notably crushing or dissolving the tablet to accelerate release. Several opioid formulations developed to be tamper resistant have been approved, but the US Food and Drug Administration has not approved explicit label claims of abuse deterrence and has stated that any such claim will require substantial postmarketing data. Drug development efforts in this area raise questions about the relative impact of abuse-deterrent formulations, not only on individuals who might abuse a medication, but also on patients who are compliant with therapy. This review discusses progress since the 2005 CPDD meeting with an emphasis on opioids. Articles cited in the review were identified via a PubMed search covering the period between January 1, 2000, and October 5, 2011. Scientific work presented by the authors and their colleagues at meetings held through May 2012 also was included. Published literature suggests that development of abuse-deterrent products will require broad public health support and continued encouragement from regulatory authorities so that such products will become the expected standard of care for certain drug classes.


Sujet(s)
Analgésiques morphiniques , Chimie pharmaceutique/tendances , Préparation de médicament/tendances , Troubles liés aux opiacés/prévention et contrôle , Analgésiques morphiniques/synthèse chimique , Analgésiques morphiniques/normes , Chimie pharmaceutique/normes , Préparation de médicament/normes , Humains , Médicaments sur ordonnance/synthèse chimique , Médicaments sur ordonnance/normes , Promédicaments/synthèse chimique , Promédicaments/normes
17.
BJOG ; 119(1): 70-7, 2012 Jan.
Article de Anglais | MEDLINE | ID: mdl-22017967

RÉSUMÉ

OBJECTIVE: To examine the effect of an exercise and dietary intervention during pregnancy on excessive gestational weight gain (EGWG), dietary habit and physical activity in pregnant women. DESIGN: Randomised controlled trial. SETTING: Community-based study. POPULATION: Nondiabetic urban-living pregnant women (<26 weeks of gestation). METHODS: Participants in the intervention group were provided with community-based group exercise sessions, instructed home exercise and dietary counselling between 20 and 36 weeks of gestation. Participants in both groups received physical activity and food intake surveys at enrolment and 2 months after the enrolment. MAIN OUTCOME MEASURES: Prevalence of EGWG and measures of physical activity and food intakes between the two groups. RESULTS: A total of 190 pregnant women, 88 in the control group and 102 in the intervention group, completed the study. Decreased daily intakes of calorie, fat, saturated fat and cholesterol were detected in participants in the intervention group at 2 months after enrolment compared with the control group (P<0.01). Participants in the intervention group had higher physical activity 2 months after enrolment compared with the control group (P<0.01). The lifestyle intervention during pregnancy reduced the prevalence of EGWG in the intervention group compared with the control group (P<0.01) according to the guidelines of the Institute of Medicine. CONCLUSION: The findings suggest that lifestyle intervention during pregnancy increased physical activity, improved dietary habits and reduced EGWG in urban-living pregnant women.


Sujet(s)
Régime alimentaire , Traitement par les exercices physiques/méthodes , Mode de vie , Complications de la grossesse/prévention et contrôle , Prise en charge prénatale/méthodes , Prise de poids/physiologie , Adulte , Assistance , Ration calorique , Femelle , Humains , Éducation du patient comme sujet , Grossesse , Issue de la grossesse , Santé en zone urbaine , Jeune adulte
18.
J R Army Med Corps ; 157(2): 156-9, 2011 Jun.
Article de Anglais | MEDLINE | ID: mdl-21805765

RÉSUMÉ

OBJECTIVES: Medical Force Protection (MFP) is important in keeping service personnel "fit to fight." It is particularly important for overseas deployment, where personnel are exposed to a range of infectious diseases. We report a full audit cycle assessing compliance with medical force protection measures, on an exercise in Belize. METHODS: An anonymous questionnaire was administered to personnel four weeks after returning from an Infantry Overseas Training Exercise (OTX) in Belize in two successive years (OTX 1 & 2). RESULTS: Compliance with physical MFP measures (mosquito nets, insecticide soak of kit and personal insect repellent usage) was excellent on both exercises. Antimalarial chemoprophylaxis compliance with a regime of weekly chloroquine and daily proguanil was poor (30%) during OTX 1. Revision of the regime to weekly chloroquine alone following review of antimalarial policies increased compliance on OTX 2 to 67%. CONCLUSION: Simplification of dosage regimes, consistency of information provided between different medical briefs and emphasis of the threat from malaria in Belize significantly improved compliance with antimalarial chemoprophylaxis.


Sujet(s)
Antipaludiques/usage thérapeutique , Chimioprévention , Paludisme/prévention et contrôle , Adhésion au traitement médicamenteux , Personnel militaire , Animaux , Belize , Chloroquine/usage thérapeutique , Doxycycline/usage thérapeutique , Humains , Morsures et piqûres d'insectes/prévention et contrôle , Insecticides , Moustiquaires , Perméthrine , Proguanil/usage thérapeutique , Vêtements de protection , Enquêtes et questionnaires , Royaume-Uni
19.
Clin Pharmacol Ther ; 89(5): 683-92, 2011 May.
Article de Anglais | MEDLINE | ID: mdl-21412231

RÉSUMÉ

Lorcaserin is a selective and potent serotonin 2C receptor subtype (5-HT(2C)) agonist under development for the treatment of obesity. This study assessed the drug's abuse potential on the basis of its pharmacological profile. For this purpose, a double-blind, double-dummy, placebo-controlled, randomized seven-way crossover study with single oral doses of lorcaserin (20, 40, and 60 mg), zolpidem (15 and 30 mg), ketamine (100 mg), and placebo was conducted in recreational polydrug users (N = 35). Subjective and objective measures were assessed up to 24 h after the dose. We found that zolpidem and ketamine had significantly higher peak scores relative to placebo on the primary measures as well as on most of the secondary measures. The subjective effects of a 20-mg dose of lorcaserin were similar to those of placebo, whereas supratherapeutic doses of lorcaserin were associated with significant levels of dislike by users as compared with placebo, zolpidem, and ketamine. Perceptual effects were minimal after administration of lorcaserin and significantly lower than after administration of either ketamine or zolpidem. The findings suggest that, at supratherapeutic doses, lorcaserin is associated with distinct, primarily negative, subjective effects and has low abuse potential.


Sujet(s)
Benzazépines/usage thérapeutique , Substances illicites , Agonistes des récepteurs 5-HT2 de la sérotonine/usage thérapeutique , Troubles liés à une substance , Adolescent , Adulte , Études croisées , Méthode en double aveugle , Femelle , Humains , Kétamine/usage thérapeutique , Mâle , Adulte d'âge moyen , Obésité/traitement médicamenteux , Obésité/psychologie , Pyridines/usage thérapeutique , Troubles liés à une substance/diagnostic , Troubles liés à une substance/prévention et contrôle , Jeune adulte , Zolpidem
20.
J Neural Eng ; 8(2): 025024, 2011 Apr.
Article de Anglais | MEDLINE | ID: mdl-21436528

RÉSUMÉ

Since the introduction of the P300 brain-computer interface (BCI) speller by Farwell and Donchin in 1988, the speed and accuracy of the system has been significantly improved. Larger electrode montages and various signal processing techniques are responsible for most of the improvement in performance. New presentation paradigms have also led to improvements in bit rate and accuracy (e.g. Townsend et al (2010 Clin. Neurophysiol. 121 1109-20)). In particular, the checkerboard paradigm for online P300 BCI-based spelling performs well, has started to document what makes for a successful paradigm, and is a good platform for further experimentation. The current paper further examines the checkerboard paradigm by suppressing items which surround the target from flashing during calibration (i.e. the suppression condition). In the online feedback mode the standard checkerboard paradigm is used with a stepwise linear discriminant classifier derived from the suppression condition and one classifier derived from the standard checkerboard condition, counter-balanced. The results of this research demonstrate that using suppression during calibration produces significantly more character selections/min ((6.46) time between selections included) than the standard checkerboard condition (5.55), and significantly fewer target flashes are needed per selection in the SUP condition (5.28) as compared to the RCP condition (6.17). Moreover, accuracy in the SUP and RCP conditions remained equivalent (∼90%). Mean theoretical bit rate was 53.62 bits/min in the suppression condition and 46.36 bits/min in the standard checkerboard condition (ns). Waveform morphology also showed significant differences in amplitude and latency.


Sujet(s)
Cartographie cérébrale/méthodes , Électroencéphalographie/méthodes , Potentiels évoqués cognitifs P300/physiologie , Potentiels évoqués visuels/physiologie , Masquage perceptif/physiologie , Stimulation lumineuse/méthodes , Cortex visuel/physiologie , Algorithmes , Calibrage , Signaux , Humains , Interface utilisateur
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